Heat pumps are gaining broader acceptance as a more economic and ecologically-friendly alternative to electric heaters. Conventional sealed system technology typically utilizes a heat pump that relies on compression and expansion of a fluid refrigerant to receive and reject heat in a cyclic manner so as to effect a desired temperature change or i.e. transfer heat energy from one location to another. This cycle can be used to provide e.g., for the receiving of heat from the environment and the rejecting of such heat elsewhere. A variety of different fluid refrigerants have been developed that can be used with the heat pump in such systems.
While improvements have been made to such heat pump systems that rely on the compression of fluid refrigerant, at best such can still only operate at about forty-five percent or less of the maximum theoretical Carnot cycle efficiency. Also, some fluid refrigerants have been discontinued due to environmental concerns. The range of ambient temperatures over which certain refrigerant-based systems can operate may be impractical for certain locations. Other challenges with heat pumps that use a fluid refrigerant exist as well.
Accordingly, a dishwasher appliance with features for efficiently heating and/or cooling a wash chamber of the dishwasher appliance would be useful. In particular, a dishwasher appliance with features for efficiently heating and/or cooling a wash chamber of the dishwasher appliance without requiring compression of fluid refrigerant would be useful.